Nano-bio convergence unveiled: Systematic review on quantum dots-protein interaction, their implications, and applications.

Quantum dots (QDs) are semiconductor nanocrystals (2-10 nm) with unique optical and electronic properties due to quantum confinement effects. They offer high photostability, narrow emission spectra, broad absorption spectrum, and high quantum yields, making them versatile in various applications. Due to their highly reactive surfaces, QDs can conjugate with biomolecules while being used, produced, or unintentionally released into the environment. This systematic review delves into intricate relationship between QDs and proteins, examining their interactions that influence their physicochemical properties, enzymatic activity, ligand binding affinity, and stability. The research utilized electronic databases like PubMed, WOS, and Proquest, along with manual reviews from 2013 to 2023 using relevant keywords, to identify suitable literature. After screening titles and abstracts, only articles meeting inclusion criteria were selected for full text readings. This systematic review of 395 articles identifies 125 articles meeting the inclusion criteria, categorized into five overarching themes, encompassing various mechanisms of QDs and proteins interactions, including adsorption to covalent binding, contingent on physicochemical properties of QDs. Through a meticulous analysis of existing literature, it unravels intricate nature of interaction, significant influence on nanomaterials and biological entities, and potential for synergistic applications harnessing both specific and nonspecific interactions across various fields.

Biofilm Inhibition on Medical Devices and Implants Using Carbon Dots: An Updated Review.

Biofilms are an intricate community of microbes that colonize solid surfaces, communicating via a quorum-sensing mechanism. These microbial aggregates secrete exopolysaccharides facilitating adhesion and conferring resistance to drugs and antimicrobial agents. The escalating global concern over biofilm-related infections on medical devices underscores the severe threat to human health. Carbon dots (CDs) have emerged as a promising substrate to combat microbes and disrupt biofilm matrices. Their numerous advantages such as facile surface functionalization and specific antimicrobial properties, position them as innovative anti-biofilm agents. Due to their minuscule size, CDs can penetrate microbial cells, inhibiting growth via cytoplasmic leakage, reactive oxygen species (ROS) generation, and genetic material fragmentation. Research has demonstrated the efficacy of CDs in inhibiting biofilms formed by key pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Consequently, the development of CD-based coatings and hydrogels holds promise for eradicating biofilm formation, thereby enhancing treatment efficacy, reducing clinical expenses, and minimizing the need for implant revision surgeries. This review provides insights into the mechanisms of biofilm formation on implants, surveys major biofilm-forming pathogens and associated infections, and specifically highlights the anti-biofilm properties of CDs emphasizing their potential as coatings on medical implants.

Synergistic reduction of nitrophenols by Au-CDs nanoconjugates with NaBH4.

Developing sustainable and innovative approaches for the efficient reduction of nitrophenols is crucial for environmental remediation, for managing health concerns posed by their widespread presence as hazardous pollutants in industrial effluents and contaminated water. We report the use of 12.9 ± 1 nm (TEM data) sized gold carbon dot nanoconjugates (Au@CDs) for catalytic conversion of o, m, p-nitrophenols to aminophenols by sodium borohydride. A simple approach was followed to synthesize ultra-small and highly stable Au@CDs, using citric acid and PEG as reducing and stabilizing agents. X-ray diffraction analysis verified the formation of nano-crystalline nanoconjugates. These nanoconjugates showed a remarkable catalytic activity in the range of 0.22-0.33 s-1(varying with nanoconjugate concentration) which was much higher compared to conventional chemical methods of reduction. All the catalytic reaction experiments were performed at room temperature (27 ± 2 °C). Furthermore, an increase in rate constant was observed with increasing concentration of nanoconjugates. The catalytic activity of Au@CDs nanoconjugates was observed to be in order of m-nitrophenol > o-nitrophenol > p-nitrophenol with apparent rate constant (kaap) values of 0.068, 0.043 and 0.031, respectively. Comparative analysis with GNPs, CDs and Au@CDs nanoconjugates stated that the nanoconjugates had superior catalytic activity. The research can have significant implications in the development of new strategies for environmental remediation and biomedical applications.

Assessing the impact and mechanisms of environmental pollutants (heavy metals and pesticides) on the male reproductive system: a comprehensive review.

The escalation of technological advancements, coupled with the increased use of hazardous chemicals, has emerged as a significant concern for human health. Exposure to environmental pollutants like heavy metals and pesticides (insecticides, herbicides and fungicides) is known to significantly contribute to various health problems, particularly affecting reproductive health. Disturbances in reproductive potential and reproductive toxicity in males are particularly worrisome. Existing literature suggests that exposure to these environmental pollutants significantly alters male reproductive parameters. Thus, it is imperative to thoroughly analyze, comprehend, and evaluate their impact on male reproductive toxicity. Oxidative stress and disruptions in redox equilibrium are major factors through which these pollutants induce changes in sperm parameters and affect the reproductive system. Insecticides, fungicides, and herbicides act as endocrine disruptors, interfering with the secretion and function of reproductive hormones such as testosterone and luteinizing hormone (LH), consequently impacting spermatogenesis. Additionally, heavy metals are reported to bio-accumulate in reproductive organs, acting as endocrine disruptors and triggering oxidative stress. The co-operative association of these pollutants can lead to severe damage. In this comprehensive review, we have conducted an in-depth analysis of the impact of these environmental pollutants on the male reproductive system, shedding light on the underlying mechanisms of action.

Biocompatible gelatin/carbon dot nanocomposite based urea sensor and the effect of nitrogen ion implantation.

In this study, we have fabricated a novel platform for sensing of urea using gelatin/carbon dots nanocomposite system. The sensor electrode was created by depositing the nanocomposite gel onto thin glass plates coated with indium tin oxide (ITO) using the drop casting technique. The behavior of these electrodes was investigated against a number of bioanalytes in the concentration range of 2-20 mM by cyclic voltammetry. The system was observed to be highly selective for urea with a sensitivity of 1.65 µA/mM/cm in the experimental linear range of 2-20 mM. Furthermore, the gelatin/CD-ITO electrode were also subjected to 50 KeV N2+ ion beam irradiation with varying fluence in the range of 1012 to 1016 ions/cm2. Sensing profile of the irradiated samples for urea suggested enhancement in sensitivity to 2 µA/mM cm2, when the ion fluence was 5 × 1015 ions/cm2. This enhancement after irradiation suggests a clear dependence of detection on the fluence of the ion beam. The observed excellent sensitivity of radiation processed nanocomposite material can be used as an enzyme-free platform for urea detection. Additionally, the CDs showed fluorescence quenching on treatment with mere 50 µM urea suggesting the high sensitivity of the platform.

Bioaccumulation of CdSe Quantum Dots Show Biochemical and Oxidative Damage in Wistar Rats.

Cadmium selenium quantum dots (CdSe QDs) with modified surfaces exhibit superior dispersion stability and high fluorescence yield, making them desirable biological probes. The knowledge of cellular and biochemical toxicity has been lacking, and there is little information on the correlation between in vitro and in vivo data. The current study was carried out to assess the toxicity of CdSe QDs after intravenous injection in Wistar male rats (230 g). The rats were given a single dose of QDs of 10, 20, 40, and 80 mg/kg and were kept for 30 days. Following that, various biochemical assays, hematological parameters, and bioaccumulation studies were carried out. Functional as well as clinically significant changes were observed. There was a significant increase in WBC while the RBC decreased. This suggested that CdSe quantum dots had inflammatory effects on the treated rats. The various biochemical assays clearly showed that high dose induced hepatic injury. At a dose of 80 mg/kg, bioaccumulation studies revealed that the spleen (120 g/g), liver (78 g/g), and lungs (38 g/g) accumulated the most. In treated Wistar rats, the bioretention profile of QDs was in the following order: the spleen, liver, kidney, lungs, heart, brain, and testis. The accumulation of these QDs induced the generation of intracellular reactive oxygen species, resulting in an alteration in antioxidant activity. It is concluded that these QDs caused oxidative stress, which harmed cellular functions and, under certain conditions, caused partial brain, kidney, spleen, and liver dysfunction. This is one of the most comprehensive in vivo studies on the nanotoxicity of CdSe quantum dots.

Exposure, toxicological mechanism of endocrine disrupting compounds and future direction of identification using nano-architectonics.

Endocrine-disrupting compounds (EDC) are a group of exogenous chemicals that structurally mimic hormones and interfere with the hormonal signaling cascade. EDC interacts with hormone receptors, transcriptional activators, and co-activators, altering the signaling pathway at both genomic and non-genomic levels. Consequently, these compounds are responsible for adverse health ailments such as cancer, reproductive issues, obesity, and cardiovascular and neurological disorders. The persistent nature and increasing incidence of environmental contamination from anthropogenic and industrial effluents have become a global concern, resulting in a movement in both developed and developing countries to identify and estimate the degree of exposure to EDC. The U.S. Environment Protection Agency (EPA) has outlined a series of in vitro and in vivo assays to screen potential endocrine disruptors. However, the multidisciplinary nature and concerns over the widespread application demand alternative and practical techniques for identifying and estimating EDC. The review chronicles the state-of-art 20 years (1990-2023) of scientific literature regarding EDC's exposure and molecular mechanism, highlighting the toxicological effects on the biological system. Alteration in signaling mechanisms by representative endocrine disruptors such as bisphenol A (BPA), diethylstilbestrol (DES), and genistein has been emphasized. We further discuss the currently available assays and techniques for in vitro detection and propose the prominence of designing nano-architectonic-sensor substrates for on-site detection of EDC in the contaminated aqueous environment.

Gold-carbon dot (Au@Cd) nanoconjugates based electrochemical sensing of cholesterol and effect of nitrogen ion implantation on sensitivity.

Serum cholesterol dysregulation is associated with prognosis and diagnosis of many diseases and effective biosensor will improvise their management. A novel electrochemical biosensor was fabricated based on gelatin-Au@CD nanoconjugate films for cholesterol detection. Initially, the surface of indium titanium oxide (ITO) coated glass was modified by drop casting of gelatin-Au@CD nanoconjugates to prepare the electrodes. Electrochemical studies for detection of bioanalytes(such as urea (U), ascorbic acid (AA), oxalic acid (OA), gallic acid (GA), cholesterol (Chox), dextrose (D), l-cysteine (Cys) and citric acid (CA)) were performed using cyclic voltammetry. The presence of nanoconjugates provided an appropriate environment for enhanced electrochemical response for cholesterol. These electrodes exhibited a linear response towards the presence of cholesterol in the linear concentration range of 2-20 mM with a correlation coefficient of 0.95, and the superior sensitivity of 1.36 µA/mM/cm2. Additionally, enhanced sensitivity (2.99 µA/mM/cm2) of nitrogen ion irradiated films up to a fluence of 1016 ions/cm2 was noticed because of morphological changes in the electrode surface brought about by irradiation. Approximately 54% enhancement was found when the ion fluence was 1016 ions/cm2. The designed nanoconjugate electrode showed excellent response towards cholesterol sensing and eliminates the requirement of any enzymes making the overall process simpler, cost-effective and allows for room temperature storage.

Comparative In Vitro Cytotoxicity Study of Carbon Dot-Based Organometallic Nanoconjugates: Exploration of Their Cell Proliferation, Uptake, and Localization in Cancerous and Normal Cells.

Organometallic nanoconjugates have raised great interest due to their bimodal properties and high stability. In the present study, we analyzed the cytotoxicity property of carbon dots (CDs) and a series of organometallic nanoconjugates including gold@carbon dots (Au@CDs) and silver@carbon dots (Ag@CDs) synthesized via an aqueous mode. We aimed to divulge a comparative analysis of cell proliferation, uptake, and localization of the particles in HeLa and HEK293 cell lines. Our results showed dose-dependent cytotoxicity of Au@CDs, Ag@CDs, and CDs. However, Ag@CDs showed the highest inhibition through HeLa cells with an IC50 value of around 50 ± 1.0 µg/mL. Confocal imaging signified the uptake of the particles suggested by blue fluorescence in the interior region of HeLa cells. Furthermore, the TEM micrographs depicted that the particles are entrapped by endocytosis assisted through the cell microvilli. The CDs and Au@CDs were thus observed to be relatively safe up to a concentration of 100 µg/mL and did not induce any morphological changes in the cells. Moreover, the cell proliferation assay of these nanoconjugates against HEK 293 cells signified the nontoxic nature of the nanoconjugates. The results thus revealed two major facts: firstly, the Ag@CDs had potent therapeutic potential, signifying their potential as a promising anticancer drug, and secondly, the CDs and Au@CDs at a defined dose could be used as probes for detection and also bioimaging agents.

Cumulative effects of manganese nanoparticle and radiofrequency radiation in male Wistar rats.

Radiofrequency radiation (RFR) is a type of non-ionizing electromagnetic radiation that includes radiowaves and microwaves with a frequency range between 3 KHz and 300 GHz. Mobile phones operate with RFR and are used tremendously resulting in increased and continuous exposure of humans to these radiations. On the other hand, nanoparticles are also being used extensively in various fields. The increasing use of radiofrequency radiations and nanoparticles has become a concern to the general public. Not many studies have reported the cumulative effect of these stressors. Hence, the present investigation was aimed to find out their cumulative effect on the mammalian system. In this study manganese nanoparticles (MNPs) were synthesized and characterized. Adult male Wistar rats were exposed to MNPs and mobile phone radiation for 45 days and their separate, as well as cumulative impact, was investigated. The effect of the MNPs and RFR on liver, kidney, and reproductive parameters were studied. Histopathology as well as liver and kidney parameters were altered when exposed to MNPs and RFR separately. However, their combined treatment did not show a synergistic toxic response in liver and kidney functions which may be due to the fact that the radiation level is low, specific absorption rate (SAR) is subthermal (0.04 W/kg) and liver and kidney are located intra abdominally, hence they would absorb comparatively lesser radiation than the testicles. MNPs and RFR both caused a highly significant decrease in sperm count, which further decreased in the combined treatment (MNPs + RFR). These results indicate that the combined treatment of these stressors can have an additive toxic response to the male reproductive system.

Metal accumulation and health risk assessment in wastewater used for irrigation around the Agra Canal in Faridabad, India.

Wastewater application for irrigation is a traditional and economic tool in developing nations. Yet prolonged use of wastewater for agricultural activities contributes to the accumulation of metals in both soil and vegetables. This study investigated the accumulation and contamination of vegetables with heavy metals ensuing from the application of wastewater from the Agra Canal and the associated risks posed to human health. Three sites across the Agra canal were selected for sampling (CW-1, CW-2, and CW-3), where untreated wastewater is being used to irrigate vegetables (spinach, coriander, radish, and garlic crops), for which tube-well water (TW) from a village served as the control site. Water, soil, and vegetable samples were collected from all sites. The presence in them of various metals, such as As, Pb, Cr, Mn, Cu, Zn, and Ni, was detected at all four sites. The greatest content of Mn was found in CW-1's water (7.91 mg/L), soil (633.77 mg/kg), and in spinach 368.12 (mg/kg) grown there. Significantly higher metal concentrations were observed in vegetables irrigated with wastewater than in tube-well-irrigated vegetables, with the metals ranked in accumulation as follows Mn > Zn > Ni > Cu > Cr > Pb > As. Our results also revealed that metal bioaccumulation varied enormously between foliar and non-foliar vegetables, as well as among the four sites. Daily metal intake (DMI) and health risk index (HRI) analyses suggested that children consuming contaminated vegetables are at higher risk than adults. The HRI for Mn, Ni, and Pb was above 1, which indicated significant health hazards to humans consuming the wastewater-irrigated vegetables. Moreover, the control site where tube-well water was used had an HRI below 1, signifying a negligible health risk for its consumption. Therefore, we may conclude that the extensive application of contaminated water for a longer duration would likely further increase metal accumulation in soil and vegetables that may be hazardous to living organisms.

Impact of nonionizing electromagnetic radiation on male infertility: an assessment of the mechanism and consequences.

PURPOSE: Environment and lifestyle factors are being attributed toward increased instances of male infertility. Rapid technological advancement, results in emission of electromagnetic radiations of different frequency which impacts human both biologically as well as genetically. Devices like cell phone, power line and monitors emit electromagnetic radiation and are a major source of the exposure. Numerous studies describe the detrimental consequence of radiation on physiological parameters of male reproductive system including sperm parameters (morphology, motility, and viability), metabolism and genomic instability. While the thermal and nonthermal interaction of nonionizing radiations with biological tissues can't be ruled out, most studies emphasize the generation of reactive oxygen species. Oxidative stress alters redox equilibrium and disrupts morphology and normal functioning of sperms along with declination of total anti-oxidant capacity. CONCLUSION: In this paper, we describe a detailed literature review with the intent of analyzing the impact of electromagnetic radiation and understand the consequence on male reproductive system. The underlying mechanism suggesting ROS generation and pathway of action has also been discussed. Additionally, the safety measures while using electronic gadgets and mobile phones has also been presented.

Recent innovations of nanotechnology in water treatment: A comprehensive review.

Environmental pollution from organic and inorganic pollutants poses a threat to the ecosystem. Pollutant's prevalence and persistence have increased significantly in recent years. In order to enhance the quality of naturally accessible water to a level suitable for human consumption, a number of techniques have been employed. In this context, the use of cutting-edge nanotechnology to classical process engineering paves the way for technical encroachments in advanced water and wastewater technology. Nanotechnology has the potential to ameliorate the quality, availability, and viability of water supplies in the long run by facilitating reuse, recycling and remediation of water. The promising role of nanotechnology in wastewater remediation is highlighted in this paper, which also covers current advancements in nanotechnology-mediated remediation systems. Moreover, nano-based materials such as nano-adsorbents, photocatalysts, nano-metals and nanomembranes are discussed in this review of recent breakthroughs in nanotechnologies for water contaminant remediation.

Metal-Fungus interaction: Review on cellular processes underlying heavy metal detoxification and synthesis of metal nanoparticles.

The most adverse outcome of increasing industrialization is contamination of the ecosystem with heavy metals. Toxic heavy metals possess a deleterious effect on all forms of biota; however, they affect the microbial system directly. These heavy metals form complexes with the microbial system by forming covalent and ionic bonds and affecting them at the cellular level and biochemical and molecular levels, ultimately leading to mutation affecting the microbial population. Microbes, in turn, have developed efficient resistance mechanisms to cope with metal toxicity. This review focuses on the vital tolerance mechanisms employed by the fungus to resist the toxicity caused by heavy metals. The tolerance mechanisms have been basically categorized into biosorption, bioaccumulation, biotransformation, and efflux of metal ions. The mechanisms of tolerance to some toxic metals as copper, arsenic, zinc, cadmium, and nickel have been discussed. The article summarizes and provides a detailed illustration of the tolerance means with specific examples in each case. Exposure of metals to fungal cells leads to a response that may lead to the formation of metal nanoparticles to overcome the toxicity by immobilization in less toxic forms. Therefore, fungal-mediated green synthesis of metal nanoparticles, their mechanism of synthesis, and applications have also been discussed. An understanding of how fungus resists metal toxicity can provide insights into the development of adaption techniques and methodologies for detoxification and removal of metals from the environment.

Modulatory effects of Punica granatum L juice against 2115 MHz (3G) radiation-induced reproductive toxicity in male Wistar rat.

Advancements in telecommunication sector result in increasing exposure to electromagnetic (EM) radiation, which has been correlated with incidence of male infertility. Therefore, the present study focused on analyzing the consequence of EM radiation (2115 MHz) exposure on the reproductive system of male Wistar rats. Besides, the antioxidant protective effect of Punica granatum juice was also evaluated. For experimental analysis, rats were divided into five groups (control, sham exposed, exposed, herbal plus exposed, and herbal only). Individual group consisted of 6 rats which were exposed to radiation for 45 days (2 h/day). The herbal-treated groups were given 1 ml of Punica granatum extract orally. Various parameters such as organ to body ratio, sperm count, motility, viability, and testis histopathology were studied. Furthermore, oxidative stress parameters and free radical generation were analyzed. The exposed group showed changes in sperm parameters along with decrease in seminiferous tubule diameter. On the contrary, herbal-exposed group showed enhanced sperm count, increased motility, and viability in comparison to exposed group. Histopathology studies also revealed the protective role of herbal juice. Significant alteration in oxidative parameters along with an enhanced free radical generation in exposed group and reduction in herbal groups was observed. The results thus indicate that continuous exposure to EM radiation can lead to oxidative stress which induces biochemical changes in rat sperms. However, Punica granatum extract has a protective role against oxidative damage induced by EM radiation.

Acid-Liable Cleavage of Doxorubicin@Plunoric-Carbon Dots in Multiplexed Bioimaging and Drug Delivery.

This study reports the generation of novel, aqueous-dispersible plunoric-CD nanoconjugates encapsulating doxorubicin (Dox). The fluorescent CD were conjugated with plunoric F127 to form biocompatible delivery matrix and were further loaded with fluorescent Dox molecule. The resulting particles were analyzed for multiplexed bioimaging and targeted drug delivery. Physicochemical and optical characterization demonstrated discrete fluorescence from CD (blue emission) and Dox (orange emission) counterparts. In vitro drug release profile signifies higher and rapid release of Dox from Dox@Plu-CD under acidic conditions compared to physiological pH. Thus, the acid liable Dox@Plu-CD linkage can easily break in the cytosol of tumor cells because of low pH compared to normal cells thus conferring minimal damage to healthy cells. Moreover, results form in vitro cell viability assay suggest the cyto-compatibility of Plu-CD delivery matrix to HEK293 and HeLa cell lines. However, Dox@Plu-CD induced cell death and morphological alterations in HeLa cell lines, signifying pH-responsive effect of the prepared complex. Confocal imaging signified that Dox@Plu-CD effectively penetrates HeLa cells, and the released Dox binds to the cell nucleus and induces oxidative stress. The prepared Dox@Plu-CD thus behaved as efficient fluorescent probes allowing multiplexed bioimaging (blue and orange) of HeLa cells along with improved therapeutic potential.Graphical abstract.

Effective and selective removal of heavy metals from industrial effluents using sustainable Si-CD conjugate based column chromatography.

The present investigation deals with the green synthesis of aqueous-stable and highly fluorescent carbon dots (CD) by hydrothermal treatment of tender leaf extract of Ficus benghalensis. The synthesized CD was characterized. Carbon dots were of an average size of 2.28 nm with a blue-green fluorescence emission at 317 nm and showed high selectivity and specificity for iron and nickel amongst the different tested heavy metals with a LOD of 0.0015 µmol/mL and 0.000014 µmol/mL respectively. Further, we functionalized silica with the prepared carbon dot to generate an adsorbent for purification of contaminated water. A short bed adsorbed column system was designed for determining the efficiency of adsorption. As envisioned approximately, 77% and 74% removal of Fe and Ni was observed when the metal salts were eluted individually. Purification efficacy was analysed using an industrial electroplating effluent, which showed adsorption of 74% and 79% for Fe and Ni respectively.

pH responsive doxorubucin loaded zein nanoparticle crosslinked pectin hydrogel as effective site-specific anticancer substrates.

Herein, we report pH-responsive hydrogels of hierarchically self-assembled protein (zein, in the form of its nanoparticles of size 80-120 nm) and polysaccharide (pectin), where gelation occurred below pH 3 in the absence of crosslinkers, which we used for encapsulation and release of anticancer drug, Doxorubicin (DOX) in the cell nucleus. These nanoparticles, spherical in shape, in addition to helping in the formation of gel network also encapsulate the drug and pectin layer adsorbed on the surface of these nanoparticle allows for the drying, redispersion and enhanced swelling. A monovalent salt-dependent study performed in the concentration range of 1-100 mM clearly showed the associative interaction between the zein nanoparticles and pectin chains were hydrophobic in nature. FTIR results confirmed the loading of the drug inside the nanoparticles. Melting profile studies of these gels revealed that encapsulation of drug did not change the thermo-physical properties. Doxorubicin drug loaded hydrogels exhibited superior cytotoxicity towards cervical cancer cell lines by inducing intracellular-antioxidative stress-based apoptosis. Confocal microscopy revealed that the hydrogels required quite less time of 4 h to completely penetrate the cells assisted by the charge specific electrostatic interaction between the negatively charged HeLa cells and positively charged crosslinks. The data, further revealed that these pH specific hydrogels were suitable for release of the drug in cell nucleus is assisted by the acidic environment of cellular organelles, and hence have a potential in cancer therapy with minimal collateral damage to healthy cells.

Dual-probe (colorimetric and fluorometric) detection of ferritin using antibody-modified gold@carbon dot nanoconjugates.

A dual-mode assay is described for immunological determination of the anemia biomarker ferritin. It is based on the use of a gold@carbon dot (Au@CD) nanoconjugate as a colorimetric and fluorescent probe. Au@CD is hydrophilic, easily surface modified and stable in aqueous solution. The Au@CD have a red color with blue-green fluorescence and were modified with antibody against ferritin. This allows bi-modal detection of ferritin. Assays can be performed in phosphate buffer and were also analyzed in (Bovine Serum Albumin) BSA and (Fetal Bovine Serum) FBS. Detection is based on antigen-antibody interaction underlying the classical sandwich model. Response to ferritin can be detected by spectrophotometry (at 570 nm) or fluorescence (at excitation/emission maxima of 354/454 nm). Under optimal conditions, the assay has a linear response in the 1 to 120 ngmL-1 ferritin concentration range and detection limits of 20 ng (colorimetrically) and 64 ng (fluorometrically). Graphical abstract Schematic representation of the function of the designed nanoprobe. The Au@CD nanoconjugates are functionalized with ferritin antibody in the initial step which specifically interacts with ferritin molecules leading to aggregation and subsequent changes in the optical and fluorescence signals.